Quadrilaterals & Symmetry
Interior Angle Calculations
Using the formula, calculate the Sum of the Interior Angles for
- A Hexagon (n=6)
- A Heptagon (n=7)
- A Dodecagon (n=12)
- An Enneaconta-heptagon (n=97)
Sum\ of\ Interior\ Angles = (n-2)\times 180
What is the Sum of EXTERIOR Angles? 🧐

Symmetry of Ice
Crystal Structure of Ice
Symmetry of a Square, Pentagon, Hexagon, and Everything Else
- Identify order of rotational symmetry
- Identify planes of mirror symmetry

Symmetric 3D Shapes are found in Nature (e.g. Quartz)

Quartz
https://www.mindat.org/min-3337.html
Other Crystals
http://phys.bspu.unibel.by/static/infoteka/cryst/minerals.html
Platonic Solids!
https://mathigon.org/course/polyhedra/platonic

S2 Quadrilaterals
By Jay Teach
S2 Quadrilaterals
- 42